Multiple Orifice Implantable Heart Valve and Methods of Implantation

ABSTRACT

A surgically implantable multiple orifice heart valve having a valve frame with at least two orifices, each of which can accommodate a tissue valve.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority to U.S. Provisional ApplicationNo. 61/123,337, filed Apr. 8, 2008, and titled “Double OrificeImplantable Heart Valve”, the entire contents of which is incorporatedherein by reference in its entirety.

TECHNICAL FIELD

The present invention relates generally to devices and methods forrepair of heart valves, and more particularly to prosthetic heart valvesfor use in replacement of the mitral valve.

BACKGROUND

One of the two atrio-ventricular valves in the heart is the mitralvalve, which is located on the left side of the heart and which forms ordefines a valve annulus and valve leaflets. The mitral valve is locatedbetween the left atrium and the left ventricle, and serves to directoxygenated blood from the lungs through the left side of the heart andinto the aorta for distribution to the body. As with other valves of theheart, the mitral valve is a passive structure in that it does notitself expend any energy and does not perform any active contractilefunction.

The mitral valve includes two moveable leaflets that open and close inresponse to differential pressures on either side of the valve. Ideally,the leaflets move apart from each other when the valve is in an openposition, and meet or “coapt” when the valve is in a closed position.However, problems can develop with valves, which can generally beclassified as either stenosis, in which a valve does not open properly,or insufficiency (also called regurgitation), in which a valve does notclose properly. Stenosis and insufficiency may occur concomitantly inthe same valve. The effects of valvular dysfunction vary, with mitralregurgitation or backflow typically having relatively severephysiological consequences to the patient. Regurgitation, along withother abnormalities of the mitral valve, can increase the workloadplaced on the heart. The severity of this increased stress on the heartand the patient, and the ability of the heart to adapt to it, determinethe treatment options that are available for a particular patient. Insome cases, medication can be sufficient to treat the patient, which isthe preferred option when it is viable; however, in many cases,defective valves have to be repaired or completely replaced in order toadequately restore the function of the heart.

One situation where repair of a mitral valve is often viable is when thedefects present in the valve are associated with dilation of the valveannulus, which not only prevents competence of the valve but alsoresults in distortion of the normal shape of the valve orifice.Remodeling of the annulus is central to these types of reconstructiveprocedures on the mitral valve. When a mitral valve is repaired, theresult is generally a reduction in the size of the posterior segment ofthe mitral valve annulus. As a part of the mitral valve repair, theinvolved segment of the annulus is diminished (i.e., constricted) sothat the leaflets may coapt correctly on closing, and/or the annulus isstabilized to prevent post-operative dilatation from occurring. Eitherresult is frequently achieved by the implantation of a prosthetic ringor band in the supra annular position. The purpose of the ring or bandis to restrict, remodel and/or support the annulus to correct and/orprevent valvular insufficiency. Such repairs of the valve, whentechnically possible, can produce relatively good long-term results.

However, valve repair is sometimes either impossible, undesirable, orhas failed, such as in cases where the problem is not related todilation of the valve annulus, leaving valve replacement as the mostviable option for improving operation of the mitral valve. The twogeneral categories of valves that are used for mitral valve replacementare mechanical valves and bioprosthetic or tissue valves. A wide varietyof mechanical valves are available that accommodate the blood flowrequirements of the particular location where they will be implanted;however, the use of these mechanical devices in the body can increasethe risk of clotting in the blood stream, which can lead to a heartattack or stroke. Thus, mechanical valve recipients must takeanti-coagulant drugs for the rest of their lives to minimize thepotential of blood clots. The use of tissue valves advantageouslyeliminates the need for such anti-coagulant drugs; however, tissuevalves do not typically last as long as mechanical valves and may needto be replaced at some later point in the patient's life. To implanteither mechanical or tissue valves, a surgical procedure is typicallyused that involves opening the patient's chest to access the mitralvalve through the left atrium, and then implanting the new valve inposition.

To simplify surgical procedures and reduce patient trauma, there hasbeen a recent increased interest in minimally invasive and percutaneousreplacement of cardiac valves. Such a replacement of a heart valvetypically does not involve actual physical removal of the diseased orinjured native heart valve, but instead includes delivery of areplacement valve in a compressed condition to the native valve site,where it is expanded. One example of such a replacement procedure for apulmonary valve includes inserting a replacement pulmonary valve into aballoon catheter and delivering it percutaneously via the vascularsystem to the location of a failed pulmonary valve. There, thereplacement valve is expanded by a balloon to compress the native valveleaflets against the right ventricular outflow tract, thereby anchoringand sealing the replacement valve. In the context of percutaneouspulmonary valve replacement, U.S. Patent Application Publication Nos.2003/0199971 A1 and 2003/0199963 A1, both filed by Tower, et al.,describe a valved segment of bovine jugular vein, mounted within anexpandable stent, for use as a replacement pulmonary valve. As describedin the articles: “Percutaneous Insertion of the Pulmonary Valve”,Bonhoeffer, et al., Journal of the American College of Cardiology 2002;39: 1664-1669 and “Transcatheter Replacement of a Bovine Valve inPulmonary Position”, Bonhoeffer, et al., Circulation 2000; 102: 813-816,a replacement pulmonary valve may be implanted to replace nativepulmonary valves or prosthetic pulmonary valves located in valvedconduits. Other implantables and implant delivery devices also aredisclosed in published U.S. Patent Application Publication No.2003/0036791 A1 and European Patent Application No. 1 057 460-A1.

The percutaneous valve implantation procedures described above typicallyinvolve the movement of a compressed valve through at least some portionof the vasculature of the patient to the delivery site, and aretherefore particularly well-suited for implanting relatively smallvalves, such pulmonary valves or aortic valves. Because a replacementmitral valve is typically relatively large as compared to the portionsof the anatomy through which it would need to travel to reach the regionof the native mitral valve, the percutaneous valve implantationprocedures described in the above journal articles may not be feasiblefor a mitral valve. However, there is a continued desire to be able tobe able to improve mitral valve replacement devices and procedures toaccommodate the physical structure of the heart without causing unduestress to the patient during the operation on the heart, such asproviding devices and methods for replacing the mitral valvepercutaneously.

SUMMARY

One embodiment of the invention is a surgically implantable multipleorifice heart valve having a valve frame with at least two orifices,each of which can accommodate a tissue valve. The outer peripheral shapeof the valve frame can be modeled for implantation in the mitral valveposition, and can therefore be generally circular, oval, or ellipticalin shape, with at least two adjacent orifices or openings. The orificesin one embodiment are generally circular in shape, although they canhave a different shape than circular, if desired. Each of the orificeswithin a single valve frame may have the same size and shape as each ofthe other orifices of that valve frame, or the orifices within a singlevalve frame can each have a different size and/or shape than the otherorifices of that frame in order to adapt to the size and shape of thenative valve opening.

A bi-leaflet valve, tri-leaflet valve, or differently configured valvecan be mounted within each opening. Each of the individual valves aredesigned for generally simultaneous opening and closing of the multiplevalves that are mounted in the same valve frame. That is, regardless ofthe leaflet structure provided, each of the heart valves should beoriented and designed so that all of the valves within a single valveframe can open and close at generally the same time within the heartcycle in response to changes in blood flow. In this way, the multiplevalves function in generally the same manner as the native valve or as asingle replacement valve in the patient. In particular, when theleaflets of both valves are in an open position, an internal passage isdefined by each orifice through which blood can flow, and when theleaflets of both valves are in a closed position, the internal passagesthrough the orifices do not allow for the flow of blood through thevalves. With specific reference to the mitral valve, the leaflets of thevalves of the multiple orifice heart valve will generally function insuch a way that blood flows toward the left ventricle when the leafletsare in an open position, and so that blood is prevented from movingtoward the left atrium when the leaflets are in a closed position.

It is also within the scope of the invention that the two or moreorifices of a valve configuration used in a single valve opening in apatient can be independent such that they can move at least slightlyrelative to each other. That is, two or more separate orifice structurescan be implanted into a single valve space in such a way that movementof the orifice structures relative to each other may be possible duringand after implantation.

If a tri-leaflet valve is attached within any of the orifices, threecommissure posts can extend from one side of the valve frame and bespaced from each other around each of the orifices. The commissure postsdefine the juncture between adjacent tissue and/or synthetic leafletssecured to the valve frame. Similar or different structures can beprovided to extend from or otherwise be attached to the valve frame forother valve configurations (e.g. for bi-leaflet valves). In someembodiments, it is possible for one or more commissure posts to beshared by adjacent valve structures.

The valve frame is the structure of the multiple orifice heart valvethat provides a means of fixing the prosthetic heart valve to thepatient's native heart valve orifice tissue (e.g., native annulus orvalvular rim) that is associated with the native heart valve beingrepaired or replaced. The valve frame includes a base portion around orover which a suture material (e.g., a cloth-like material) is disposedfor suturing the prosthesis to heart tissue. The suture or cloth-likematerial portion may also cover any support structures, such as thecommissure posts described above.

It is contemplated that the valve frames of the invention are initiallyimplanted without any attached valve structures. The valves cansubsequently be delivered in a minimally invasive manner to the orificesin the valve frame and attached via coalescent clips or other means.

Once the valve frame with attached valve structures (e.g., theprosthetic heart valve with multiple orifices, as described above) isimplanted within the patient, the valve can be expected to functionwithout problems for a period of time, and possibly as long as severalyears, without any noticeable issues. However, if deficiencies occur atany time after implantation in one or more of the valves of themultiple-valve structure, each deficient valve can potentially bereplaced by percutaneously delivering a new valve via transcatheterimplantation. Each of these individual valves would be relatively smallas compared to the overall valve size that would be required forpercutaneous implantation of a comparable mitral valve that fills themitral valve space. In this way, the complications and risks involvedwith additional surgical intervention can be minimized or avoided.Another advantage of using multiple valves with a smaller size insteadof one larger diameter valve is that the protrusions or other extendingstructures of the stent frame can be somewhat smaller. Thus, theprotrusions will not extend as far into the ventricle when the device isimplanted, thereby reducing the potential for obstruction or damage tothe ventricle and/or the native valvular apparatus, such as chordae orpapillary muscles.

The invention further includes a method of surgically implanting amultiple orifice valve assembly into the mitral valve area of a patient,then percutaneously delivering a replacement valve, such as a stentedvalve, to at least one of the orifices of the surgically implanted valveassembly. Each percutaneously delivered replacement valve can includefeatures for proper orientation and positioning relative to the orificeof the surgically implanted heart valve. For one example, thepercutaneously delivered valve can include a stent having dockingfeatures that are designed or selected to cooperate with features of thevalve frame for secure anchoring of the elements relative to each other.Thus, it is within the scope of the invention for the valve frame of themultiple orifice valve assembly to have specific features or elementsthat allow for a certain type of engagement with a replacement valvehaving corresponding features. In that regard, the multiple orificevalve assembly and replacement valves can be provided as a kit. With anyof the embodiments described above, the valve frames, stents, and othercorresponding elements should be provided so that there is minimalinterference with the functioning of an adjacent aortic valve. Inaddition, while many of the embodiments are shown and described ashaving two orifices in a valve frame, it is understood that the valveframes may include three or more orifices, which can help to accommodatethe anatomies of patients having particularly large mitral openings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be further explained with reference to theappended Figures, wherein like structure is referred to by like numeralsthroughout the several views, and wherein:

FIG. 1 is a bottom perspective view of one embodiment of a valve framein accordance with the invention;

FIG. 2 is a top plan view of the valve frame of FIG. 1 and illustratingexemplary valve leaflets in their closed positions;

FIG. 3 is a top plan view of another embodiment of a multiple-orificevalve assembly of the invention;

FIG. 4 is a top plan view of another embodiment of a multiple-orificevalve assembly of the invention;

FIG. 5 is a perspective view of a distal portion of a delivery systempositioned relative to one orifice of a portion of a mitral valvereplacement assembly;

FIG. 6 is a top schematic plan view of another embodiment of amultiple-orifice valve assembly of the invention;

FIG. 7 is a top plan view of another embodiment of a multiple-orificevalve assembly of the invention; and

FIG. 8 is a top plan view of a tri-orifice valve assembly of theinvention.

DETAILED DESCRIPTION

Referring now to the Figures, wherein the components are labeled withlike numerals throughout the several Figures, and initially to FIGS. 1and 2, one embodiment of a double orifice implantable heart valve 10 inaccordance with the invention is illustrated. Although the heart valvesof the invention, such as heart valve 10, are generally described hereinas being used for mitral valve replacement, it is understood that manyof the features of these heart valves can be used for valves in otherareas of the heart. For example, the heart valves of the invention canbe used in any area of the heart where it would be more advantageous touse multiple valves that are relatively small than to use a single valvethat is relatively large. In any case, the heart valves of the inventiondesirably restore normal functioning of a cardiac valve, and areinitially implanted using surgical techniques that include minimallyinvasive methods or more traditional open-heart surgical methods.Further, as used throughout this specification, a “prosthetic heartvalve” or “heart valve” is intended to encompass bioprosthetic heartvalves having leaflets made of biological material (e.g., harvestedporcine valve leaflets, or bovine or equine pericardial leaflets), alongwith synthetic leaflet materials or other materials.

Heart valve 10 includes a valve frame 12 having a first orifice 14 and asecond orifice 16. These orifices 14, 16 are illustrated to be generallythe same size and shape as each other, and preferably are sized forattachment of a tissue valve within each of their interior portions.FIG. 2 illustrates the valve frame 12 with a first tri-leaflet valve 18in its closed position within the first orifice 14 and a secondtri-leaflet valve 20 in its closed position within the second orifice16. This three-leaflet arrangement of valves 18, 20 is exemplary;alternative configurations include a bi-leaflet valve positioned in bothof the orifices, and valves that are different from each other in eachof the orifices (e.g., one of the orifices includes a three-leafletvalve while the other orifice includes a bi-leaflet valve). In any case,the multi-orifice valve configurations of the invention advantageouslyallow for replacement of only one of the valves if only one of thevalves fails at some point after implantation (while at least oneproperly functioning valve remains operational), as will be described infurther detail below. If such a valve replacement is performed, thespecific rotational orientation of the valve leaflets within the orificemay or may not be a consideration.

Referring again to FIG. 1, the valve frame 12 has an outer peripherythat is generally oval or elliptical in shape and has a first side 24and an opposite second side 26. The valve frame 12 is generally shapedor modeled to match the valve space into which it will be surgicallyimplanted. For example, if the valve frame 12 will be placed in themitral valve space of a patient, characteristics of the specific mitralvalve space into which it will be positioned can be taken into account.Thus, the valve frame 12 may have a generally planar surface on itsfirst and second sides 24, 26, or it may have contours and shaping onone or both sides to match the anatomy of the patient. For example, itmay be relatively saddle shaped. The valve frame 12 provides a means forfixing the double orifice implantable heart valve 10 to the patient'snative heart valve orifice tissue (e.g., the native annulus or valvularrim) that is associated with the native heart valve being repaired orreplaced. In particular, a surgical implantation technique can beemployed whereby the heart is stopped (e.g., with the use ofcardiopulmonary bypass) and opened, which is followed by optionalsurgical removal of damaged or diseased natural valve structure. Theheart valve 10 can then be oriented within the native valvular area,with the valve frame 12 being seated against or at the native annulus orvalvular rim. Sutures can then be used to affix the valve frame 12 tothe natural tissue.

With the various multiple valve assemblies of the invention, it isdesirable to maximize the overall area of the orifices relative to theframe size in order to minimize the obstruction to blood flow. Thus, itis preferable that the sizes of the structural components of the stentframe are minimized, while the desired structural strength of the frameis maintained.

The first and second orifices 14, 16 are spaced from each other acrossthe width of the valve frame 12, and the spacing and exact orientationof the orifices 14, 16 can be selected to provide desired performancecharacteristics for the valve. For example, the orifices 14, 16 can begenerally circular in shape and arranged relative to their valve frame12 so that the center points of the orifices 14, 16 generally coincidewith a central axis that runs across the width of the valve frame 12.However, it is understood that the orifices 14, 16 can be at leastslightly offset relative to the central axis of the valve frame 12and/or that they can be at least slightly offset relative to each other.The orifices 14, 16 can be at least slightly spaced from each other, asshown, thereby providing a central area of the valve frame 12 betweenthe two orifices 14, 16. Preferably, the portions of the heart valveassembly 10 between the orifices is impermeable to blood flow to resistregurgitation. The illustrated space between the orifices 14, 16 is oneexemplary configuration, and can be smaller or larger than shown.Alternatively, there may be no space between two adjacent orifices 14,16. Longitudinal axes that extend through the orifices (generally in thedirection of blood flow) can be generally parallel to each other suchthat the orifices and corresponding valves lie in the same plane.Alternatively, the longitudinal axes of the orifices may be at leastslightly offset relative to each other so that the orifices are at leastslightly tilted or tipped toward or away from each other within thevalve frame.

As discussed above, in the exemplary embodiment of FIGS. 1 and 2, thevalve frame 12 includes two tri-leaflet valves 18, 20. In order toprovide the structure for attachment of these valves, multiplecommissure posts 28 extend from the first side 24 of the valve frame 12.In particular, three commissure posts 28 are positioned around each ofthe orifices 14, 16, where the posts 28 can be spaced generally evenlyfrom each other around the orifices 14, 16, or they can be unevenlyspaced, depending on the characteristics of its corresponding valve. Thecommissure posts can be rigid yet somewhat flexible structures, whichcan be covered with a cloth-like material. The commissure posts definethe juncture between adjacent tissue or synthetic leaflets that aresecured within an orifice.

The valves provided in the valve frames described herein may use apreserved bovine jugular vein of the type described in the above-citedBonhoeffer, et al. and Tower, et al. references. However, other vesselsor donor species may alternatively be used for various reasons. Forexample, in order to provide additional valve strength in the relativelyhigh-pressure conditions that exist in the mitral valve area of theheart, pericardial valves, polymeric valves, or metallic valves mayalternatively be used in a tricuspid or bicuspid leaflet configuration.

FIG. 3 illustrates another embodiment of a double orifice implantableheart valve 30, which includes two prosthetic valves 32, 34 surroundedby a valve frame 36. In this embodiment, valves 32, 34 can each includestent structures of the type used in areas of the heart that accommodaterelatively small, circular valves, such as the pulmonic valve. The valveframe 36 may be a gasket or other member that surrounds the outermostperiphery of the valves 32, 34 to provide for sealing againstparavalvular leakage and to facilitate pannus in-growth forstabilization of the heart valve 30. The valve frame 36 also preferablyprovides enough structural strength to position and maintain the valves32, 34 in their desired arrangement relative to each other. The frame 36can be relatively rigid to prevent most or all movement of the valves32, 34 relative to each other, or the frame 36 can be relativelyflexible to allow at least some movement of the valves 32, 34 relativeto each other.

Another embodiment of a double orifice implantable valve assembly 100 isshown in FIG. 6. Valve assembly 100 includes a frame 102 from which twopairs of commissure posts 104 extend. Each commissure post 104 ispositioned with another commissure post 104 located across from it ongenerally the opposite side of the frame 102. Each pair of commissureposts 104 provides the attachment areas for a bi-leaflet valve, wherethe frame 102 illustrates a first bi-leaflet valve 106 and a secondbi-leaflet valve 108. As shown, valves 106, 108 are attached directly tothe frame 102 in such a way that they do not have their own frames orstents. The valves can thus contact each other at least slightly in thecentral area of the stent frame, as illustrated. Since there is noadditional stent structure internal to the frame 102, the size of thevalves can be maximized relative to the opening in the frame 102.

The individual valves of the double orifice implantable heart valvesdescribed herein are generally shown and described as being cylindricalin shape; however, a number of different stent shapes are alsocontemplated, such as valves that are oval or elliptical in shape.Another exemplary alternative configuration is illustrated in FIG. 4with a double orifice implantable heart valve 50 that includes a firstprosthetic valve 52 and a second prosthetic valve 54, both of which aresurrounded by a valve frame or gasket 56. Each of these two valves 52,54 has a curvilinear surface that can be designed to generally match theshape of the ends of the annulus of a mitral valve, and a generally flator planar surface that results in more “squared off” corners where theflat surface meets the curvilinear surface. The flat surfaces of thevalves 52, 54 are in contact with each other along at least a portion oftheir lengths at a central area 58. This arrangement provides for lessgaps or openings between the individual valves in a multiple valvearrangement than when circular valves are used. The heart valve 10 ofFIG. 1 may alternatively include orifices that are shaped similarly tothe valves 52, 54 of this embodiment in order to utilize valves that aresomewhat D-shaped.

Another exemplary configuration of an implantable heart valve assemblyof the invention includes a valve frame having two or more individualvalves having different sizes and/or shapes from each other. Forexample, one or both of the valves can be at least slightly elliptical,oval, D-shaped, square, or differently shaped in cross-section when intheir expanded conditions. For another example, one of the valves withina valve frame can be at least slightly larger than the other valve orvalves of that frame, which would correspond to the orifices in whichthey are attached. In some cases, the differently sized and/or shapedorifices can help to better adapt the multiple-orifice heart valve tothe native valve opening. The shape of the valves can be designed andselected to provide a proper fit to the patient's anatomy.

Another exemplary multiple orifice valve assembly 120 is illustrated inFIG. 7. Valve assembly 120 includes a first valve 122 and a secondadjacent valve 124, both of which are tri-leaflet valves positionedwithin a stent frame 126. Stent frame 126 includes a number ofcommissure posts extending from one of its surfaces that act as theattachment points for the leaflets of the valves 122, 124. Inparticular, the leaflets of valve 122 are attached at commissure posts128, 130, 132, and the leaflets of valve 124 are attached at commissureposts 132, 134, 136. Thus, the relatively central stent post 132 isshared by both of the valves 122, 124, thereby providing a relativelylarge orifice size inside the stent frame 126 with minimal obstructionsto blood flow. A similar configuration can alternatively be used withtwo bi-leaflet valves in a single stent frame, where one of thecommissure posts of the assembly is common to both valves. In yetanother alternative embodiment, a stent assembly may include onebi-leaflet and one tri-leaflet valve, where both of the valves share onecommon commissure post.

Other valve assembly arrangements can include more than two valveswithin a single stent frame, as is contemplated by the presentinvention. For one example, three valves 150, 152, 154 are illustratedwithin a stent frame 156 in FIG. 8. The valves 150, 152, 154 are shownas having an intermediate stent or strut portion between each twoadjacent valves; however, any of the other features described hereinrelative to stent assemblies with two valves can also be utilized instent frames with three or more valves. Such multiple valve assembliescan include bi-leaflet valves, tri-leaflet valves, combinations of bi-and tri-leaflet valves that do not include intermediate strut portions,and the like.

Once a valve frame of the invention having attached valve structures(e.g., one of the prosthetic heart valve with multiple orificesdescribed above) is implanted within the patient, the valve can functionfor a period of time with no noticeable issues. However, if deficienciesoccur at any time after implantation in one or more of the valves of themultiple-valve structure, each deficient valve can be replaced bypercutaneously delivering a new valve via transcatheter implantation.The invention further includes a method of surgically implanting amultiple orifice valve assembly into the mitral valve area of a patient,then percutaneously delivering a replacement valve to at least one ofthe orifices of the surgically implanted valve assembly. Each of theseindividual valves would be relatively small as compared to the overallvalve size that would be required for percutaneous implantation of acomparable mitral valve that fills the mitral valve space, therebybetter facilitating percutaneous implantation through a variety ofaccess sites. The replacement valve can be a stented valve that includesan outer stent structure to which a valve structure is attached.

FIG. 5 illustrates a distal portion of an exemplary delivery system 70as it is delivering a replacement stented valve 72 (shown schematicallyas only a stent of the valve) to a double orifice heart valve 80 that isdepicted by two adjacent heart valves 74, 76. Heart valves 74, 76 arethe two orifices of the double orifice heart valve 80 of the invention.The device or structure that attaches these valves to each other isgasket or frame 78. That is, the heart valves 74, 76 are intended torepresent the two orifices of a single structure 80 that wouldpreviously been implanted into a patient, where the single structurecould have been implanted to replace a mitral valve, for example. FIG. 5represents the situation where some failure or malfunction of theleaflets of heart valve 74 has occurred, thereby necessitating areplacement of that heart valve. In accordance with the invention, it ispossible to replace only this valve 74 of the two-valve system with areplacement stented valve 72, although it may be desirable or necessaryto replace both valves 74, 76 with new replacement stented valves. Thevalve replacement procedure can advantageously be accomplished using apercutaneous valve delivery system.

In order to reduce potential stresses on the valve frames describedherein and to reduce potential stresses on the associated annulus, it isalso possible to provide multiple orifice structures that can move atleast slightly relative to each other within a single native opening. Inparticular, the valves may be moveable relative to a defined planeand/or may be moveable to be positioned closer or further from eachother during and after implantation. In such an embodiment, the stentframes can be made of flexible materials, such as metals, (e.g.,Nitinol), polymers, or tissue-based materials.

The stented valves used to replace a deficient valve using the methodsof the invention can correspond generally to a stent of the typedescribed in the above-cited Tower, et al. and Bonhoeffer et al.references, for example, although it is understood that a wide varietyof stent configurations can be used in accordance with the invention.The replacement stented valves may include a stent structure that isfabricated of platinum, stainless steel, Nitinol, an alloy of the typecommercially available under the trade designation MP35N, or otherbiocompatible metal. The replacement stented valves may alternatively befabricated using wire stock as described in the above-cited Tower, etal. applications, or the stented valves may be produced by machining orlaser cutting the stent from a metal tube, as is commonly employed inthe manufacturing of stents. The number of wires, the positioning ofsuch wires, and various other features of the stents can varyconsiderably from that shown in the figures. In another alternative, thevalves used to replace a deficient valve may be stentless valves.

In any case, the replacement stented valves used in the methods of theinvention are preferably compressible to a relatively small diameter forinsertion into a patient, but are also at least slightly expandable fromthis compressed condition to a larger diameter when positioned in adesired location in the patient. It is further preferable that theprocess of compressing the stented valves does not permanently deformthe stent in such a way that expansion thereof would be difficult orimpossible.

Any of the stent assemblies discussed herein can further includestructures that provide a fixation function for securing the stentassembly in its desired location relative to the orifice of a previouslyimplanted heart valve. For example, the stent assembly can includehooks, barbs, or the like that attach to a structure of a valve orificeupon deployment of the stent assembly.

A portion of an exemplary system that can be used to implant a stentedvalve of the types described above includes an elongated ballooncatheter having an inflatable balloon that is connected for fluidcommunication with a lumen that extends through the length of thecatheter. The lumen provides for inflation and deflation of the balloonwith a fluid, such as a radio-opaque fluid, during the process ofdeploying a stented valve within a patient. The delivery system mayinclude a thin guide wire that extends generally along the length of thecatheter, which may be used in a conventional manner to guide thecatheter to its desired implant location. When the components of thesystem are positioned relative to the orifice of a patient, a balloonmay be inflated to thereby expand the stent to the desired size relativeto the orifice in which it will be positioned. After such stentexpansion is complete, the balloon can be deflated and the system canthen be withdrawn from the patient.

It is further contemplated that two or more percutaneous valves can besimultaneously or sequentially delivered to a multiple orifice stentusing a delivery system that has multiple balloons. For example, if bothvalves of a double-orifice valve are to be replaced at the same time, adelivery system having two balloons can be used to deliver both valvessimultaneously.

The replacement heart valves, along with the multiple-orificeimplantable heart valves of the present invention may be positionedwithin the desired area of the heart via entry in a number of differentways. In one example, the valves may be inserted transatrially, whereentry may be done either percutaneously or in a minimally invasivetechnique on a beating heart in which access is through the side of theheart, or even through a standard open heart valve replacement procedureusing heart-lung bypass and sternotomy where the described device wouldbe used as an alternative to the standard replacement. In anotherexample, the valves may be inserted transapically, where entry again maybe done either percutaneously or in a minimally invasive technique on abeating heart in which access is through the side of the heart. In yetanother example, the valves may be inserted transeptally, where entrycan be done percutaneously, such as via the venous system into the rightatrium and across a small hole in the septum to enter the left atrium.In yet another example, the valves may be inserted transfemorallythrough the arterial system. It is also possible that the deliveryapproaches may include balloons that would be used to facilitate thecrossing of the mitral valve, thereby avoiding entanglement in themitral apparatus.

It is also contemplated that the stented valves of the present inventionare self-expanding such that pressure is required to maintain the valvein its compressed condition, and removal of such pressure will allowthese stented valves to expand to their desired size. In these cases,the delivery system will be somewhat different than that described aboverelative to stents that are not self-expanding, and will instead includea system that only requires removal of external pressure (e.g., acompressive sheath) to allow the stented valves to expand, such as isthe case with the delivery of stent grafts for aneurysms in theascending aorta. These systems may also incorporate means forrecapturing and/or repositioning the stented valve, if desired. In anycase, it may be desirable to measure the mitral valve area with sometype of spacer prior to installing the actual stent assembly in theheart of the patient.

The stented valves may further include a means of facilitatingorientation of the assembly relative to the orifice in which they willbe implanted, which can be particularly advantageous in cases where thestented valves include asymmetric features and configurations that mustbe properly oriented relative to the anatomy of the patient. To thatend, the stented valves may include portions with materials that areopaque when viewed with various imaging techniques, such as echogeniccoatings and radiopaque metals and polymers. Additionally oralternatively, the material used to fabricate the stent itself may behighly visible when using certain imaging techniques so that the userhas a clear visibility of the orientation of the device prior to andduring deployment.

The present invention has now been described with reference to severalembodiments thereof. The foregoing detailed description and exampleshave been given for clarity of understanding only. No unnecessarylimitations are to be understood therefrom. It will be apparent to thoseskilled in the art that many changes can be made in the embodimentsdescribed without departing from the scope of the invention. Thus, thescope of the present invention should not be limited to the structuresdescribed herein.

1. A stent assembly for implantation in a body lumen, the stent assemblycomprising: a stent frame comprising a first opening, a second openingspaced from the first opening, and a first intermediate strut portionpositioned between the first and second openings.
 2. The stent assemblyof claim 1, wherein the intermediate strut portion is impermeable toblood flow.
 3. The stent assembly of claim 1, wherein each of the firstand second openings comprises a tissue valve.
 4. The stent assembly ofclaim 1, wherein each of the first and second openings are circular. 5.The stent assembly of claim 1, wherein the frame further comprises atleast two commissure posts extending from a first side of the frame andadjacent to the first opening, and at least two commissure postsextending from the first side of the frame and adjacent to the secondopening.
 6. The stent assembly of claim 1, wherein the size of the firstopening is different from the size of the second opening.
 7. The stentassembly of claim 1, wherein the stent frame is relatively rigid forsurgical implantation into a patient.
 8. The stent assembly of claim 7,wherein the stent frame has an outer shape that is compatible with theshape of a mitral valve in which it will be implanted.
 9. The stentassembly of claim 1, further comprising a third opening adjacent to andspaced from the second opening, and a second intermediate strut portionpositioned between the second and third openings.
 10. A stent assemblycomprising a first stent barrel, a second stent barrel adjacent to thefirst stent barrel, and a stent frame surrounding an outermost peripheryof the first and second stent barrels.
 11. The stent assembly of claim10, wherein the stent frame is rigid such that the first and secondstent barrels are not moveable relative to each other within the stentframe.
 12. The stent assembly of claim 10, wherein the stent frame isflexible such that the first and second stent barrels are moveablerelative to each other within the stent frame.
 13. The stent assembly ofclaim 10, wherein at least one of the first and second stent barrels iscylindrical.
 14. The stent assembly of claim 10, wherein the first andsecond stent barrels have generally the same cross-sectional shape andsize.
 15. The stent assembly of claim 10, wherein the first stent barrelhas a different cross-sectional shape than the second stent barrel. 16.A stent assembly for implantation in a body lumen, the stent assemblycomprising: a stent frame comprising first and second commissure postsextending from a first side of the frame and positioned on generallyopposite edges of the frame, a first valve attached to the first andsecond commissure posts, third and fourth commissure posts extendingfrom the first side of the frame and positioned on generally oppositeedges of the frame, and a second valve attached to the third and fourthcommissure posts.
 17. The stent assembly of claim 16, further comprisinga fifth commissure post positioned between the first and second valves,wherein each of the first and second valves is further attached to thefifth commissure post.
 18. A method of replacing a surgically implantedmultiple orifice valve assembly in a patient, comprising the step ofpercutaneously delivering a replacement valve to at least one orifice ofthe valve assembly, wherein each replacement valve comprises at leastone anchoring structure that is engageable with at least one dockingfeature of the multiple orifice valve assembly.
 19. The method of claim18, wherein a replacement valve is delivered to each of the orifices ofthe multiple valve assembly.
 20. The method of claim 18, wherein eachreplacement valve is a compressible and expandable stented heart valve.